Combination overshot rotary milling-cutter.



D. L. DRISCOLL.

COMBINATION OVERSHOT ROTARY MILLING CUTTER.

APPLICATION FILED 00T- 8,1917- u Patented Jan. 8, 1918.

:NVENTOR. I

Quay 64%;,

A TTORNE YS.

UNITED STATES PATENT OFFICE.

DENNIS L. DRISCOLL, OF COALINGA, CALIFORNIA, ASSIGNOB OF ONE-HALF TOHUNTING IRON WORKS, QF COALINGA, CALIFORNIA, A CORPORATION OFCALIFORNIA.

COMBINATION OVEBSHOT ROTARY MILLING-CUTTER.

Specification 'of Letters Patent.

Patented Jan. 8, 1918.

Application filed October 8, 1917. Serial No. 195,286.

their supporting pipe strings employed in the drilling of oil wells bythe rotary process. In the drilling of oil wells by the rotary process,the bit or drill is attached to the lower end of a string pipe or othertion the boring of the hole into the oil sands is accomplished. Owing tothe extreme depth of some of the drilling operations the i e strin orsup ort becomes very long, En d due ti its gre zit length often bucklesor twists off, and at times when the pipe is removed from the soil Orwell and thesections thereof are separated to change the drilling tool,portions of it often dro to the bottom of the well and become twistedand bent therein and unless removed it is necessary to either drillaround the same or abandon the well.

The resent invention has for its principal ob ects to provide a toolparticularly designed for removing these broken,v separated, or twistedsections of drilling pipe or support from the well, to provide aconstruction which is adapted for cutting its way over the end of thepipe and to cause the same to pass upwardly through the tool, to provideengaging means on the inner surface of the tool for engaging the pipe toassist in raising the same from the hole, or if required, to enable thepipe to be cut free at alpoint of connection with another 'section or inthe main body portion thereof, to provide a construction wherein thepipe cutting ,and engaging devices are adapted to pass freely over thepipe'on the lowering of the tool and which will immediately engage thesame when the tool is drawn upwardly a slight distance over the pipe.

With the above mentioned and other objects view, the invention consistsin the novel construction and combination of parts hereinafterdescribed'illustrated in the ac companying drawings, and set forth inthe claims hereto appended; it being understood that various changes inthe form, proportion, size and minor details of construction within thescope of the claims may be resorted to without departing from the spiritor sacrificing any of the advantages of the invention.

To more fully comprehend the invention, reference is directed to theaccompanying drawings, wherein,

Figure 1 is a vertical sectional view of the preferred embodiment of myinvention. support which is rotated and by thls rota- Fig. 2 is atransverse sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is a view in detail plan of one of the cuttingand engaging dogs.

Fig. 4 is a view in detail of a modified form of cutting and engagingdogs.

Referring more particularly to the several views of the drawings,wherein like characters of reference designate corresponding parts, 1,indicates a suitable tubular member preferably in the form of a pipe thelength of which depends on the number of attached sections which arepreferably secured together in the usual manner by threaded collars. Inthe carrying on of a fishing operation sections are added to the.

pipe 1, to permit the tool at the lower end thereof to be inserted intothe hole or well the required distance. On the lower end of the pipe 1,is threaded as at 2, a body 3, preferably tubular in form, and to thelower end of which is threaded as at 4, a suitable milling cutter 5,preferably of the rotary type, having the cutting teeth 5' on the lowerperipheral surface thereof. This cutter is adapted when the tool islowered into a well and rotated to cut its way over ,the pipe or supportwhich is to be fished out, thereby enabling the pipe to pass upwardlythrough the body 3 and supporting pipe 1. The body 3 is formed withsuitable vertical guide slots 6, dovetailed'in cross-section, andwhichcon verge inwardly at their inner or lower ends and are preferablyformed at their lower ends with-seat portions 7.

Vertically movable within each of these supporting guide slots 6, is asuitable block or member 8, dovetailed in cross-section and upwardlyfrom each of which through the slots 6, extends a connecting arm 9, eachsecured at its upper end to a suitable weighted collar 10, thus, it willbe ap arent, that the connecting arms 9 and co lar 10, unite each of theblocks 8. The lower faces of the blocks 8 are provided with seatportions 11, for contacting with and resting on the seat portions 7, ofthe guide 6, when the blocks are at the lower ends of guide slots 6, andsaid blocks are also formed with the upwardly beveled surfaces 12, whichpermits a free upward movement of the blocks when moved laterally bytheir upward movement in the guide 6 over any object which may passthrough the body 3.

The vertical faces 13, of the respective blocks 8, are formed withcutting edges 13 as are the upper surfaces of the horizontal portions14, of said blocks as at 14, thus when it is found that the pipe to befished out cannot be withdrawn from the hole in one piece, the weight ofthe collar 10 after the tool is passed downwardly over the pipe willcause the blocks to engage the side walls thereof and a rotary motionbeing imparted to the supporting pipe 1 the cutting edges 13 will engagethe support for the boring tool and sever the same enabling the uppersection to be fished out. Should a collar be encountered in thisoperation and a slight pull be exerted upwardly on the body, the cuttingsurfaces 14 will engage under the collar and on rotary motion beingimparted to the tool mill that portion of the collar cooperating withthe lower section, enabling the section immediately above the same andthose above it to be withdrawn from the hole. In this construction thegreater the u ward pull on the member 1 the tighter the b ocks 8 areforced into the member engaged thereby, due to the converging of theslots 6 In my construction I provide a-milling cutter 5, to assist thetool in cutting its way overthe pipe to be fished out and also providethe cutting surfaces 13' and 14 on the blocks 8 for cutting directlyinto the pipe when the face 13 is employed, or millin under a'collarwhen the face 14 is employe and said blocks carrying said cuttingdevices are also adapted due to the converging guide slots to tightlyengage the pipe to be fished out on tension being placed on the ipe 1. gIf desirable the blocks 8 may be provided with the rotary cutters 15,extending inwardly from the vertical faces thereof and supported on thevertical shaft 16.

By my improved apparatus it will be apparent that where it is found thatthe rotary drilling tool pipe or support cannot be removed in oneoperation the same may be successively cut into several sections andeach section as cut removed, the lower edge of the cut section restingon the cutting edge 14, of the respective blocks 8 when the same islifted from the hole.

Having thus described my invention what I claim as new is:

A tool for the described purpose comprising a tubular body, a millmgcutter secured to the lower end thereof, and a plurality of verticallymovable engaging blocks carried by and projecting beyond the innersurface of said body, each of said blocks provided with a cuttingsurface on the inner exposed face thereof,

Q. A tool for the described purpose, comprising a tubular body, saidbody provided in its side walls with vertically disposed guide slotsconverging at their lower ends, a vertically movable block positionedwithin each of said slots and each formed with a vertical cutting face,and a rotary cutter secured to the lower end of said body withitscutting face projecting annularly from the lower peripheral edgethereof.

3. A tool for the described purpose, comprislng a tubular body providedwith a plurality of vertically disposed guide slots converging at theirlower ends, and a vertically movable block positioned within each ofsaid slots and each formed on its inner exposed face with a cuttingsurface.

4. A tool for the described purpose comprising a tubular body formed inits side wall with a plurality of vertically disposed guide slotsopening at their lower end toward the inner face of said body and converging at their lower ends, a block vertically movable within each ofsaidguide slots and provided with a cutting ed e for extending beyondthe inner wall 0 said body, an annular member movable vertically of said.body,'an d a connection extending longitudinally of said guide slotsand uniting each of said blocks vwith said vertically movable memberwhereby said blocks will move in unison 5. A tool for the describedpurpose comits cutting faces providingthe lower annular wall surface ofsaid vtool.

6. A tool for the described purpose, comprising a. tubular body providedwith a plu- In testimony whereof I have signed my rality of verticallydisposed guides 0011- name to this specification in the presence ofverging toward the lower end of said tubutwo subscribing witnesses.

lar body, a vertically movable member DENNIS L. DRISCOLL. 5 within eachof said guides and each provided Witnesses:

on its inner exposed face with a cutting sur- Tnos. L. COLEBOURN,

W. C. YA'ms.

face.

